The present invention relates to a service unit for groupwise exchange of bobbins between a creel and a bank of a textile fly frame.
In U.S. Pat. No. 4,805,352 to Grassle et al., an apparatus is disclosed for exchanging full bobbins on a bobbin bank of a textile fly frame for empty bobbins. The apparatus includes a pivotable gripper assembly mounted to a traveling surface unit, a revolving plate means having a plurality of pegs for receiving bobbins thereon and means for raising and lowering the plate pegs to transfer bobbins between the plate pegs and a creel extending overhead the traveling service unit along its direction of travel. The full bobbins on the bobbin bank of the textile fly frame are arranged in two parallel rows and are uniformly spaced from one another along each row. The creel includes two parallel banks for supporting two parallel rows of empty bobbins in reserve and the empty bobbins are uniformly spaced with one another within each creel row. The gripper assembly is operable to simultaneously transfer a plurality of full bobbins from each of the parallel rows of the bobbin bank to two parallel rows of plate pegs on the plate means in the traveling service unit.
The raising and lowering means of the traveling service unit is operable to raise another pair of parallel rows of plate pegs toward the creel to receive a plurality of empty bobbins from each creel row and to return the thus-loaded plate pegs to the plate means. Thereafter, the plate means is revolved generally 180.degree.. The gripper assembly then grips the parallel rows of empty bobbins supported on the plate pegs to transfer these empty bobbins to the bobbin bank while the raising and lowering means raises the plate pegs with full bobbins thereon toward the creel to transfer these bobbins to the creel rows.
The uniform spacing of the full bobbins of each bobbin bank row typically is different than the uniform spacing of the empty bobbins in each creel row. Additionally, the transfer spacing between the two parallel bobbin rows typically is different than the transverse spacing between the two parallel creel rows. Accordingly, the linear spacing between the bobbins within each row and the transverse spacing between each pair of parallel bobbin rows must be adjusted as the bobbins are transferred between the creel and the bobbin bank. The Grassle et al patent discloses a parallelogram linkage for effecting such adjustments simultaneously. However, the need exists for an apparatus which relatively rapidly effects such adjustments independently to improve the efficiency of the bobbin exchange operation of a textile fly frame.